Here's the bibliography for my own German Revolution timeline. I've included the whole thing, so some of it may not be of use to you.
Wikipedia, including articles in translated foreign languages.
1914-1918 online. International Encyclopedia of the First World War.
Revolutionary Russia, academic journal published by T&F Online.
German Communists: Biographical Handbook 1918 to 1945 and Who was who in the DDR? A dictionary of East German biographies, online database from the Bundesstiftung Aufarbeitung.
Tomas Balkelis, ‘Demobilization and Remobilization of German and Lithuanian Paramilitaries after the First World War’, Journal of Contemporary History (2015).
Charles L. Bertrand, ‘The Biennio Rosso: Anarchists and Revolutionary Syndicalists in Italy, 1919-1920’, Historical Reflections (1982).
György Borsányi, The Life of a Communist Revolutionary, Béla Kun.
Pierre Broué, The German Revolution 1917-1923.
Nicholas W. Coombs, Lev Kamenev: A Case Study in ‘Bolshevik Centrism’.
Gilles Dauvé and Denis Authier, The Communist Left in Germany 1918-1921.
Ralph Darlington, ‘Syndicalism and Strikes, Leadership and Influence: Britain, Ireland, France, Italy, Spain, and the United States’, International Labor and Working-Class History (2013).
Lara Douds, Inside Lenin’s Government. Ideology, Power and Practice in the Early Soviet State.
Theodore Draper, The Roots of American Communism.
Pieter van Duin, Central European Crossroads: Social Democracy and National Revolution in Bratislava (Pressburg) 1867-1921.
John M. Foot, ‘‘White Bolsheviks’? The Catholic Left and the Socialists in Italy-1919-1920’, The Historical Journal (1997).
Weimar Communism as Mass Movement 1918-1933, edited by Ralf Hoffrogge and Norman LaPorte.
Charles R. Holm, Black Radicals and Marxist Internationalism: From the IWMA to the Fourth International, 1864-1948.
Erin K. Jenne, Ethnic Bargaining: The Paradox of Minority Empowerment.
Moshe Lewin, Lenin’s Last Struggle.
James D. White, ‘National Communism and World Revolution: The Political Consequences of German Military Withdrawal from the Baltic Area in 1918-19’, Europe-Asia Studies (1994).